Prof. Dr. med. E. Zrenner
Introduction
Since 1996 the research consortium “Subretinale Microphotodiodes” has been developing a so-called subretinal implant that is designed to give patients who became blind as a result of degenerative retinal diseases a new ability to see.
Partner of the consortium were:
- University Eye Hospital Tübingen, Dept. for Pathophysiology of Vision and Neuro-ophthalmology (Director Prof. Dr. med. E. Zrenner)
- NMI Natural and Medical Sciences Institute at the University of Tübingen (Director Prof. Dr. H.f Hämmerle)
- Institut für Mikroelektronik Stuttgart (Direktor: Prof. Dr. Joachim N. Burghartz)
- University Eye Hospital Regensburg (Director: PD Dr. med. H. Sachs)
- Institut für Physikalische Elektronik der Universität Stuttgart (Direktor Prof. Dr. rer. nat. J. H. Werner)
Thanks to the combined efforts of the research consortium, prototypes of the implants were manufactured and basic problems were solved.
- subretinal stimulation elicits neuronal activity in retinal ganglion cells.
- The parameters for successful electric stimulation were defined and went into the development process of the chips
- successful testing in retinas of animals with comparable retinal degenerations
- successful in vivo tests proving that subretinal stimulation is able to activate the corresponding cortical areas by spatial resolution
- development of two surgical procedures for implanting the chip.
- successful explantation and re-implantation experiments in various experimental animals (rabbit, cat and pig)
- Biocompatibility in animal experiments successfully demonstrated; usual foreign tissue rejection reactions and inflammations did not occur.
- Biostability in animal experiments proven for a period of up to 6 months; after 6 months, recognizable corrosion; procedure for biostable encapsulement in the testing phase; test materials show no signs of corrosion after being implanted for one year.
- Manufacture of the first generation of “active” chips.
Further literature: